leucism

noun

leu·​cism ˈlü-ˌsi-zəm 

: an abnormal condition of reduced pigmentation affecting various animals (such as birds, mammals, and reptiles) that is marked by overall pale color or patches of reduced coloring and is caused by a genetic mutation which inhibits melanin and other pigments from being deposited in feathers, hair, or skin

leucistic

lü-ˈsi-stik 

adjective

Examples of leucism in a Sentence

Recent Examples on the Web

However, leucism — a separate condition — can also produce white coloration in whales, according to LiveScience, meaning not all whales with an ivory complexion are true albinos. —Brendan Rascius, Miami Herald, 30 June 2025

The orca's pale complexion may be due to leucism or Chediak-Higashi Syndrome. —Fernando Cervantes Jr., USA TODAY, 5 Dec. 2024

This discrepancy surprised us because the genetic mutation that causes melanism occurs less frequently than the one that causes albinism/leucism. —Elizabeth Carlen, Discover Magazine, 31 Oct. 2024

On social media, some commenters speculated the creature might be a young red or gray fox with leucism, a condition that causes a loss of pigmentation, resulting in white fur. —Alexa Robles-Gil, Smithsonian Magazine, 17 Oct. 2024

Word History

Etymology

borrowed from German Leucismus, from Greek leukós "clear, white" + German -ismus -ism — more at light entry 1

First Known Use

1878, in the meaning defined above

Rhymes for leucism

• ism
• pisum
• prism
• schism
• abolitionism
• aldosteronism
• americanism
• anticommunism
• antisemitism
• antiterrorism
• bioterrorism
• colloquialism